Orientational mercury removal from aqueous solution using three-dimensionally structured CuxS nanocluster anchored attapulgite

Toxic mercury-containing wastewater emitted from mining and nonferrous metallurgy seriously threatens human health and aquatic ecosystem. Effective mercury removal interfered with other coexisting metal ions in wastewater poses major challenges, requiring simple and sustainable methods. In this work, a novel three-dimensional (3D) CuxS nanocluster-anchored attapulgite (ATP@CuxS) is tailored for orientational mercury adsorption from diluted mercury-containing wastewater. The prepared ATP@CuxS adsorbent exhibited an unparalleled Hg2+ adsorption capacity of 746.48 mg g-1 among ever-reported clay-based adsorbents. Mercury-containing wastewater with an initial concentration of 5 mg L-1, and solution pH of 6.5 was ~100% removed within 20 min, and no interference by coexisting anionic and cation ions was observed. In the determination of the adsorption mechanism, in-situ intercalation and vulcanization of Cu2+ on ATP base constructs nanoclusters shaped CuxS that provide abundant active sites for Hg2+ adsorption. The negatively charged ATP facilitates positive Cu2+ immobilization on its surface followed by inorganic sulfide generation. This interfacial electrical compatibility makes a compact and stable composite.
33 Hydrophilic ATP modulated the uniform dispersion performance of ATP@CuxS, and
34 the dense CuxS package contributed to easier sedimentation and recovery after Hg2+
35 adsorption in water. Furthermore, Hg2+ removal efficiency was maintained at 70% after
36 8 times repetitions, indicating a gentle feasibility as a mass-generated adsorbent. The
37 proposed interface engineering from the perspective of micro-interface electrical
38 compatibility creates an attractive and easily accessible system that combines efficiency,
39 capacity, selectivity, and reusability for orientational removing Hg2+ from wastewater.